The present invention relates to a head suspension assembly with a precise positioning actuator, used for a magnetic disk device, and to a method of manufacturing the assembly.
In such magnetic disk device, a thin-film magnetic head element for writing magnetic information into and/or reading magnetic information from a magnetic disk is in general formed on a magnetic head slider flying in operation above the rotating magnetic disk. The slider is supported at a top end section of a suspension extended from one end of each movable arm of the magnetic disk device.
Recently, recording density along the radial direction in the magnetic disk or along the track width direction rapidly increases to satisfy the requirement forever increasing data storage capacities and densities in today""s magnetic disk devices. Thus, it is difficult to perform correct positioning of the magnetic head with respect to the track in the magnetic disk by the control of only a voice coil motor (VCM) as the conventional art.
Techniques for realizing precise positioning of a magnetic head are described in for example U.S. Pat. No. 5,745,319 and Japanese unexamined patent publication No. 8-180623. In these techniques, another actuator mechanism is presented at a position nearer to a magnetic head slider than the conventional VCM so as to perform fine precise positioning that cannot be realized by the VCM only.
However, if such additional actuator is adopted, problems may be occurred due to lead lines between the magnetic head and the additional actuator. In a typical magnetic head, for example a composite type magnetic head with a read head part of a magnetoresistive effect (MR) transducer element and a write head part of an inductive transducer element, four or more lead lines are required for reading and writing operations and two or more additional lead lines are required for driving the actuator. Thus, it is necessary to make six or more lead lines on a suspension. Since the total width of the lead lines increases, the elasticity and the rigidity of the lead lines become large causing an attitude of the magnetic head and a movement performance of the head by mean of the actuator to affect. Furthermore, there is no space to form so many lead lines within a tongue at which the additional actuator and the magnetic head slider are attached.
The additional actuator drives the magnetic head slider to move its top end section having the magnetic head element in the track width direction. However, this movement of the slider will also produce movement at electrical connection part between the magnetic head slider and the lead lines fixed to the suspension causing an electrical or mechanical break in the coupled part.
It is therefore an object of the present invention to provide a head suspension assembly with a precise positioning actuator and a method of manufacturing the assembly, whereby an attitude a magnetic head will not be so affected by elasticity and rigidity of lead lines.
Another object of the present invention is to provide a head suspension assembly with a precise positioning actuator and a method of manufacturing the assembly, whereby a movement performance of a magnetic head by the actuator will not be so affected by elasticity and rigidity of lead lines.
Further object of the present invention is to provide a head suspension assembly with a precise positioning actuator and a method of manufacturing the assembly, whereby an electrical or mechanical break in a connection part between a magnetic head element and lead lines can be prevented from occurring.
According to the present invention, a head suspension assembly includes a magnetic head slider with at least one thin-film magnetic head element, an actuator fixed to the magnetic head slider for performing precise positioning of the at least one thin-film magnetic head element, a support member for supporting the actuator, a flexible first lead conductor member with one end electrically connected to the at least one thin-film magnetic head element, at least part of the first lead conductor member being formed on the support member, and a second lead conductor member with one end electrically connected to the actuator. At least part of the second lead conductor member is formed on the support member. The support member has a first portion on which the one end of the first lead conductor member is formed and a second portion. The first portion is individually separated from the second portion.
According to the conventional three-pieces structure suspension with a load beam, a flexure and a lead conductor formed on the flexure, if an actuator is located between the suspension and a magnetic head slider, lead lines for the magnetic head slider cannot be made as a part of the lead conductor formed on the flexure. Thus, it is necessary to use lead wires for the connection with the magnetic head slider. According to the present invention, however, the support member is divided into a first portion on which one end connected to the magnetic head slider of the first lead conductor member is formed and a second portion so that the first portion is individually separated from the second portion. Thus, it is possible to exist the first lead conductor member in different planes and therefore wireless lead conductor can be provided. Furthermore, since the first portion or a top end portion of the support member is individually separated from the second portion or the other portion, a part for establishing electrical connection with the actuator and a part for establishing electrical connection with the magnetic head element of the lead conductor member are divided. Therefore, wireless lead conductor members can be provided without introducing any interference between the movements of the lead conductor members even when the actuator displaces the position of the magnetic head element. As a result, the elasticity and the rigidity of the lead conductor members will not affect an attitude of the magnetic head. In addition, since an air-floating portion of the flexible first lead conductor member absorbs the movement of the actuator, electrical and/or mechanical break at the electrical connection part with the magnetic head element can be prevented from occurring.
Since no wired connection is used for establishing electrical connections with the actuator and the magnetic head element, no wire-forming process is needed resulting improvement in productivity and improvement in the resistance characteristics against static electricity.
It is preferred that the actuator and the magnetic head slider are located at one face side of the support member. In this case, the support member may include a resilient load beam and a resilient flexure supported by the load beam, and at least part of the first and second lead conductor members may be formed on one face of the flexure. Also, in this case, the support member may include a resilient flexure-load beam, and at least part of the first and second lead conductor members may be formed on one face of the flexure-load beam.
It is also preferred that the magnetic head slider is located at one face side of the support member and the actuator is located at the other face side of the support member. In this case, the support member may include a resilient flexure-load beam, and at least part of the first and second lead conductor members may be formed on one face of the flexure-load beam.
It is preferred that the support member has a via section, and that the actuator is connected to the one end of the second lead conductor member through the via section.
It is preferred that the first and second portions of the support member are located in different planes, and that the first lead conductor member can be freely curved from the first portion to the second portion.
It is also preferred that the first portion of the support member has at least one via hole. In this case, the actuator may be directly fixed to the magnetic head slider through the at least one via hole. The at least one via hole may be via holes for reducing a weight of the first portion.
Preferably, the one end of the first lead conductor member is directly connected to terminals of the at least one thin-film magnetic head element by ball bonding or by stitch bonding.
It is preferred that the first and second lead conductor members are formed by flexible print circuits with lead conductor layers sandwiched by insulation layers.
According to the present invention, furthermore, a manufacturing method of a head suspension assembly which includes a magnetic head slider with at least one thin-film magnetic head element, an actuator fixed to the magnetic head slider for performing precise positioning of the at least one thin-film magnetic head element, a support member for supporting the actuator, a flexible first lead conductor member, at least part of the first lead conductor member being formed on the support member, and a second lead conductor member, at least part of the second lead conductor member being formed on the support member has the steps of electrically connecting one end of the first lead conductor member to the at least one thin-film magnetic head element, electrically connecting one end of the second lead conductor member to the actuator, and thereafter, cutting the support member into first and second portions so that the first portion on which the one end of the first lead conductor member is formed is individually separated from the second portion.
If the suspension is separated before assembling it with the actuator and the slider, workability of the assembly process will be extremely reduced. However, according to the present invention, since cutting of the first portion or top end portion of the support member is performed after assembling of the magnetic head slider, the actuator and the suspension, a wireless suspension can be provided without reducing the workability of the assembly process.
It is preferred that the support member includes a resilient load beam and a resilient flexure supported by the load beam, and that at least part of the first and second lead conductor members are formed on one face of the flexure.
It is also preferred that the support member includes a resilient flexure-load beam, and that at least part of the first and second lead conductor members are formed on one face of the flexure-load beam.
It is preferred that the first lead conductor member is formed so as to be freely curved from the first portion to the second portion.
It is also preferred that the one end of the first lead conductor member is directly connected to terminals of the at least one thin-film magnetic head element by ball bonding or by stitch bonding.
Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawings.